David Blankenhorn in his new book The Future of Marriage points out something I had not noticed: proponents of homosexual marriage define marriage as the close relation of two people who love one another. They do not include sexual intercourse as part of the definition. By that standard, nearly all parents and children, grandparents and grandchildren, siblings, even most close friends would be "married."
The Future of Marriage reviews the anthropological evidence for the early origins of intense sexual attachments among human beings, which normally result in children. Blankenhorn then makes the case that marriage is a cultural achievement, created in historic times, to permanently unite these sexually bound parents to raise their children. Once invented, marriage has become a nearly universal social institution through which a man and woman turn their sexual relation into a social relation for rearing the kids that their sex produces.
Blankenhorn can only find two schools of thought that do not include sex as an essential good of marriage. The first were the early Church Fathers, who were trying to develop a theory of marriage based on the unique relationship of the Virgin Mary and Joseph. They acknowledged that sex was part of the definition of marriage, but they weren't too happy about it. The other school of marriage theorists who define marriage without praising sex are today's proponents of same-sex marriage. Indeed, Blankenhorn says, the same-sex marriage theorists are the only marriage theorists that he has ever run across who do not include sex in their definition of marriage at all. And Blankenhorn has been a professional student of marriage for twenty years.
Blankenhorn thinks that gay marriage proponents don't want to talk about sex because they don't want to talk about children -- children being the main, though not the only, focus of all marriage theories ever developed before the current moment. It occurs to me to wonder, though, if another reason to avoid spelling out the sexual point of homosexual marriage is because most people find the idea of it distasteful, even if they don't think it should be illegal. Tactically, gay marriage may sell better if the campaign is about who you love, not who you have intercourse with, or why.